A wide range of three terminal linear regulator integrated circuits are available to provide clean, constant supply voltages regulated for line and load changes. Such regulators are notoriously inefficient, and with linear regulator circuits it is not possible to get a higher output voltage than the input voltage.
Integrated circuit switching regulators have recently become available. Such regulators employ pulse width modulated switching circuits in which the regulation is achieved by an active feedback network which samples the output voltage and generates a voltage which controls the pulse width of the switcher. Switching regulators provide the ability to achieve output voltages which are higher than the input voltage and are highly efficient.
A problem encountered in switching regulators with active feedback circuits is that they are subject to overshoot of the output voltage when input power is applied or when a short is removed. This is due to the slow response of the typical feedback network. Slow responses are necessary to insure that the regulator does not oscillate.
There have been a number of solutions proposed to prevent or minimize output overshoot. These solutions are generally not satisfactory because they require extra components, do not work under all conditions, or require extra pins to be added to the integrated circuit.